Potty's not supported at the top in lodging (9)
I believe the answer is:
brainless
'potty's' is the definition.
(potty can mean mad)
'not supported at the top in lodging' is the wordplay.
'not supported at the top' becomes 'braless' (a bra provides support around where a top is worn).
'lodging' means one lot of letters goes inside another (back).
'braless' going around 'in' is 'BRAINLESS'.
(Other definitions for brainless that I've seen before include "Stupid, foolish" , "dim" , "Silly" , "Devoid of intelligence" .)